This invention relates to electrical raceways, more particularly, a puller/connector for electrical raceways having a spiral shape so as to provide symmetrical force on the electrical raceway when pulled and to provide a secure connection once the electrical raceway is housed within an electrical box.
Electrical raceways, also known as “Greenfields”, are hollow, flexible steel conduits having a plurality of crests and troughs that are used for housing electrical wires within a wall of a building. The electrical raceways have predetermined inner and outer diameters so as to house various amounts of electrical wires therein. When utilizing electrical raceways for wiring a building, the raceways are first fed through a wall of the building and directed towards an electrical box. Then, steel tape, which is a long piece of wire usually 100-200 feet in length having a hooked end, is used to pull the wires through the electrical raceway towards the electrical box.
To connect the electrical raceway to the electrical box, a “knockout”, or removable piece of the electrical box or panel that is removed to allow the electrical raceway and ires to be inserted into the electrical box through the knockout. Once inserted, a straight electrical raceway connector and lock nut are used to secure the electrical raceway within the electrical box. Once secured, the electrical raceway may also serve as a ground. Although the use of electrical raceways has many advantages, there are some drawbacks to utilizing them, specifically during the installation process.
First, although the use of steel tape allows for pulling the electrical raceway through the wall interior towards the electrical box, because the steel tape pulls on one side of the electrical raceway, kinking occurs along the electrical raceway due to the asymmetrical force exerted on one end of the electrical raceway.
Second, because the edges of the electrical raceway are usually sharp, electrical raceways typically catch on the insulation located within the wall, thereby ripping the insulation and compromising the integrity of the insulation.
Finally, although the straight electrical raceway connector and lock nut are used to secure the electrical raceway within the electrical box, because the electrical box is typically narrow in diameter, it is difficult to obtain a tight lock around the electrical raceway. If the connector and lock nut are not tightly secured around the electrical raceway, the electrical raceway slips out of the connector and lock nut over time. As the electrical raceway may also serve as a ground, a loose connection or a disconnection lessens or eliminates the ground, thereby causing dangerous conditions.
Thus, a need exists for a puller/connector for electrical raceways that is able to safely pull electrical raceways through insulation without damaging the insulation and to permanently secure the electrical raceway within the electrical box when installed.
The relevant prior art includes the following references:
Pat. No.Issue/(U.S. unlessPublicationstated otherwise)InventorDate6,863,576Campbell et al.Mar. 8, 20054,978,312FodaliDec. 18, 19903,058,083SchneiderOct. 9, 19622005/0250354VintherNov. 10, 20055,769,665Neely et al.Jun. 23, 1998916,436GreenfieldMar. 30, 19091,847,924CalderwoodMar. 1, 19324,806,108MeinhardtFeb. 21, 1989